1. Field of the Invention
This invention relates to a lever type connector assembly which interconnects and separates connectors by utilizing a cam action and more particularly to a lever type connector assembly in which a torsion coil spring for rockably biasing a lever to a given initial position is temporarily attached to one of the connectors.
2. Statement of the Prior Art
A lever type connector assembly has an advantage of interconnecting and separating connectors by a small force and particularly can be applied to multipole connectors.
For convenience of explanation, a conventional lever type connector assembly will be explained below by referring to drawings.
FIG. 10 is an exploded perspective view of a conventional lever type connector assembly. FIG. 11 is a perspective view of a lever shown in FIG. 10, illustrating a torsion coil spring mounted on a side plate of the lever. FIG. 12 is a perspective view of a female connector housing shown in FIG. 10. FIG. 13 is a fragmentary cross sectional view of the housing and lever shown in FIG. 10, illustrating a position at which an end of the torsion coil spring engages with the housing. FIG. 14 is a perspective view of a conventional torsion coil spring. FIG. 15 is a fragmentary enlarged perspective view of the lever shown in FIG. 11. FIG. 16 is a cross sectional view of the lever shown in FIG. 11, illustrating a process of attaching the torsion coil spring to the lever. FIG. 17 is a longitudinal sectional view of the lever, illustrating a process of attaching an end of the torsion coil spring into a holding slot in the lever.
An example of a conventional connector housing assembly, as shown in FIG. 10, includes one (female) connector housing 1, a lever 3 mounted rotatably on a pair of support axles 4 on the housing 1 and having cam grooves 3a, and the other (male) connector housing 2 having a pair of cam followers 5. The pair of connector housings 1 and 2 are coupled to and detached from each other when the lever 3 is turned about the axles 4 to move the cam followers 5.
In the above lever type connector assembly, in order to bias the lever 3 to a given rotary direction, a torsion coil spring 6 shown in FIG. 14 is coupled to the lever 3 and female connector housing 1, as shown in FIGS. 11 to 13. At this time, a ring portion 6a of the spring 6 (FIG. 14) is disposed around a bearing hole 3b and on an inner face of a side plate or arm 22a of the lever (see FIG. 11), an end portion 6b of the spring 6 engages with the inner face of the arm 22a (see FIG. 11), and the other end portion 6c of the spring 6 engages with a projection la on an outer face of the connector housing 1 (see FIGS. 12 and 13).
Upon constructing the above lever type connector assembly, after fitting the ring portion 6a of the torsion coil spring 6 on the support axle 4 on the connector housing 1, one end portion 6b of the spring 6 is locked on a part of the lever 3 and the other end portion 6c of the spring 6 is locked on the projection la on the connector housing. This requires very difficult work and is inefficient.
In order to avoid such difficult constructing work, the present applicant has proposed a lever type connector assembly in which the lever is provided with a pair of holding slots which accommodate opposite end portions of the torsion coil spring with it being biased, and in which one end portion of the spring accommodated in one holding slot is transferred from the slot to the connector housing after mounting the lever on the housing (Japanese Utility Model Public Disclosure No. 6-11 70. According to this assembly, it is possible to greatly facilitate the work of mounting the lever on the connector housing, since the torsion coil spring is accommodated In the holding slots beforehand and the torsion coil spring on the lever does not interfere with the connector housing upon mounting the lever on the housing.
However, although the above assembly enhances a work of mounting the lever on the connector housing, the work of attaching the torsion coil spring to the lever had to be improved.
That is, in order to attach the torsion coil spring 6 shown in FIG. 14 to the side plate 22a of the lever 3, the side plate 22a is provided in the inner face with a pair of holding slots 7 and 8 which receive opposite end portions 6b and 6c of the torsion coil spring 6 with the spring 6 being biased, as shown in FIGS. 15 and 16. First, one end portion 6b of the spring 6 is inserted into one holding slot 7 and the other end portion 6c is pushed and turned by a tool pin similar to an end of a ball pen to insert the end portion 6c into the other holding slot 8. At this time, since the other end portion 6c of the torsion coil spring 6 applies an elastic force to the tool pin 9, the tool pin 9 must be moved carefully so that the portion 6c does not leap over the tool pin 9 on account of its elastic force. Then, as shown in FIG. 17, when the end portion 6c is moved near the other holding slot 8, a distal end of the tool pin 9 must apply a downward force in addition to a forward force to the end portion 6c to push it into the other holding slot 8. Although such operation is easier than a conventional operation of mounting the lever on the connector housing while locking the torsion coil spring 6 on both of the lever and the connector housing, the former operation still requires skillful work and results in inefficiency.
In FIGS. 15 and 16, a reference number 10 is a tool aperture through which the tool pin 9 passes so that it pushes the other end portion 6c of the spring 6 in the other holding slot 8 toward the projection 1a on the connector housing 1.